Replaceable cartridge hypodermic syringe having sterile maintenance of needle

ABSTRACT

This invention is directed to a replacable cartridge hypodermic syringe in which, initially, a combined needle assembly and cartridge unit are bodily inserted into the distal end of the syringe barrel and thereafter replacement cartridges may be inserted or removed without affecting the sterility of the needle. The needle assembly includes a generally cylindrical body having a proximally extending annular skirt associated therewith for threaded retention within the distal end of the barrel. Sterility of the needle is not affected by cartridge changes.

United States Patent 1191 1111 3,838,690

Friedman 1 1 Oct. 1, 1974 1 1 REPLACEABLE CARTRIDGE 2,869,542 1/1959Orsten et a1. 128/218 D HYPODERMIC SYRINGE HAVING STERILE 3,021,9422/1962 Hamilton 128/221 X 3,043,304 7/1962 Higgins 128/218 N MAINTENANCEOF NEEDLE 3,052,241 9/1962 Myerson et a1. 128/221 [76] Inventor:Benjamin Friedman, 1064 Victory 3,224,445 12/1965 Melott 128/218 D Blvd"T Island 10301 FOREIGN PATENTS OR APPLICATIONS 1 1 Flledl 16, 1973236,613 4/1960 Australia 128/221 [211 App]. No.: 388,944

Primary ExaminerRichard A. Gaudet Related Apphcatmn Data AssistantExaminer-J. C. McGowan [63] Continuation of Ser. No. 162,497, Jul 14,1971, Attorney, Agent, or p p and Feldman abandoned.

152 US. Cl. 128/218 N, 128/218 DA, 128/221 [571 ABSTRACT A61!" AfilmThis invention is directed to a replacable cartridge hy- 1 Field OfSearch 213 podermic syringe in which, initially, a combined nee- 128/218218 218 213 dle assembly and cartridge unit are bodily inserted 215 intothe distal end of the syringe barrel and thereafter replacementcartridges may be inserted or removed References Cited without affectingthe sterility of the needle. The nee- UNITED STATES PATENTS dle assemblyincludes a generally cylindrical body hav- 1240 033 9 1917 Dickinson128/221 ing a Pmximany extending annular Skirt associated 1: 39: 95H1932 i 12 21 D therewith f0! threaded retention within the distal end1,840,788 1/ 1932 Nevin. 128/218 D of the barrel. Sterility of theneedle is not affected by 2,157,503 5/1939 Smith....., 128/218 Dcartridge changes. 2,677,373 5/1954 Barradas 128/216 2,778,359 1/1957Friedman 128/218 D 4 Claims, 10 Drawmg Figures BAIENIE UBI H9743.838.690 SHEEI 20F 2 FIG. 7 FIG. 8'

FIG. 9

FIG. IO

llllll This is a continuation of application Ser. No. 162,497, filedJuly 14, 1971, now abandoned.

THE INVENTION This invention relates generally to new and usefulimprovements in hypodermic syringes and particularly seeks to provide anovel hypodermic syringe for dentists in particular that is initiallycapable of receiving and retaining a combined needle and cartridgeassembly for an initial injection or aspiration, after which thecartridge may be removed and replaced by one or more successivelyinstalled cartridges without removing the needle and without affectingthe sterility of same.

One such general type of syringe is disclosed and claimed in myco-pending patent application Ser. No. 865,818, filed Oct. 13, 1969, nowUS. Pat. No. 3,640,278, granted Feb. 8, 1972. In that type of syringethe needle assembly must first be inserted into the bottom of the barrelfrom the inside thereof, after which the first and each successivecartridge to be used is inserted and locked into the body of the barrelin needle engaging position. This type of syringe construction, whilepermitting cartridge replacement without affecting sterility of theneedle, precludes the possibility of initially using a pre-assembledcartridge-needle unit because it is impossible to insert such a unit asan entity upwardly into the syringe barrel through the bottom or distalend thereof.

In contrast, a syringe constructed in accordance with this invention isexpressly designed to permit the initial use of a preassembledneedle-cartridge unit, when desired, while permitting successivecartridges to replace the initial cartridge without afiecting thesterility of the needle.

Therefore, an object of this invention is to provide a novel hypodermicsyringe constructed to receive and retain a combined needle assembly andcartridge unit when inserted from one end and to permit the independentremoval and replacement of the cartridge without necessitating removalof the needle assembly and without affecting sterility of the needle.

Another object of this invention is to provide a syringe of thecharacter stated that includes a longitudinally apertured barrel havingcartridge locking or clamping means and a cartridge plunger actuating orpiston rod mounted at one end and an internally threaded opposite endfor receiving and retaining as assembly including an axially aligneddouble-ended hypodermic needle.

Another object of this invention is to provide a syringe of thecharacter stated in which the needle assembly includes a generallycylindrical body formed from a plastic material that is sufficientlysoft or deformable to be self threading when engaged within theinternally threaded end of the barrel.

Another object of this invention is to provide a syringe of thecharacter stated in which the cylindrical body of the needle assembly isprethreaded for engagement within the internally threaded end of thebarrel.

' A further object of this invention is to provide a syringe of thecharacter stated in which the needle assembly therefor includes a bodyhaving a flanged base with a cylindrical skirt extending axially fromone end, a relatively small diameter, circularly cross-sectioned, studextending from its other end, a double ended hypodermic needle axiallyretained within the flanged base and the stud with one end projectingbeyond the end of the stud and its other end surrounded by thecylindrical skirt and substantially coextensive with the depth thereof,there being removable friction caps covering the skirt of said body andthe oppositely extending stud thereof for protecting the exposed ends ofthe needle.

A further object of this invention is to provide a syringe of thecharacter stated in which means are provided to operatively connect theinner end of the actuating or piston rod with the opposed plunger orpiston of a cartridge when such cartridge is installed within the barrelof the syringe.

A further object of this invention is to provide a syringe of thecharacter stated in which the cylindrical body portion of the needleassembly may be enclosed by a cover assembly including a skirted elementthat surrounds the skirt of the needle assembly for engagement withinthe internally threaded end of the barrel.

A further object of this invention is to provide a syringe of thecharacter stated that is simple in design, rugged in construction andeconomical to manufacture.

With these and other objects, the nature of which will be apparent, theinvention will be more fully understood by reference to the drawings,the accompanying detailed description and the appended claims. In thedrawings:

FIG. I is an exploded longitudinal section of a hypodermic syringeconstructed in accordance with this invention;

FIG. 2 is an enlarged longitudinal detail section of the needle assemblyshown in FIG. 1 and illustrates one form in which the needle assemblymay be made and pre-packaged for self-threading insertion into thebarrel of the syringe;

FIG. 3 is a view similar to FIG. 2 but shows how the skirt of the needlebody cover may be pre-threaded;

FIG. 4 is a view similar to those of FIGS. 2 and 3 but shows how theskirt of the needle body itself may be pre-threaded in order toeliminate one cover element for pre-packaging purposes;

FIG. 5 is a fragmentary longitudinal section showing the initiallyinstalled combined needle assembly and cartridge, with the type ofneedle assembly being that of either FIGS. 2 or 3;

FIG. 6 is a view similar to FIG. 5 but indicating the removal of theinitially installed cartridge for replacement by a subsequentlyinstalled cartridge;

FIGS. 7 and 8 are fragmentary detailed longitudinal sections showingvarious means for operably connecting the actuating or piston rod of thesyringe with the plunger or piston of the associated cartridge; and

FIG. 9 is a view similar to those of FIGS. 24 but showing a furthermodification in the construction of the body of the needle assembly formore rapid engagement within the barrel of the syringe.

FIG. 10 is a proximal end view of the needle assembly of FIG. 9 with thecap removed.

Referring to the drawings in detail the invention, as illustrated, isembodied in a hypodermic syringe including a cylindrical barrel 5 havingan externally threaded upper or proximal end 6 and an internallythreaded lower or distal end 7.

One wall section of the barrel is provided with a longitudinal apertureor window 8, having a length and width sufficient to permit the readyinsertion of cartridges, and the opposite wall section of the barrel isprovided with a shorter aperture or window 9 located near the proximalend of the barrel to enable a users finger to be inserted to displacethe upper or proximal end of a cartridge when it is to be replaced by afresh cartridge.

Cartridge clamping and plunger or piston actuating means are attached tothe proximal end of the barrel 5 and include a finger nut 10 that isthreadably connected to and seated on the proximal end 6 and is provideda threaded axial bore that is adapted to receive and retain a generallycylindrical axiably adjustable clamp element 11 having a cylindricalrecess 12 at its distal end for engagement over the proximal end of aninstalled cartridge and an oppositely extending knurled knob 13 at itsproximal end. A flange l4 limits the distal retractive movement of theelement 11 while permitting full proximal movement thereof, even to thepoint of disengagement from the finger nut 10.

The clamp element 11 is provided with an axial bore 15 into which isfreely fitted a relatively long actuating or piston rod 16 having afinger ring 17 removably affixed to its proximal end and means generallyindicated 28 at its distal end for operative connection with the plungeror piston of an installed cartridge, as will be hereinafter more fullydescribed.

A collar 19 is affixed adjacent the distal end of the rod 16 to preventthe rod from being distally retracted completely from the bore 15, thusnecessitating removal and replacement of the finger ring 17 duringinitial assembly in order to permit the rod to be inserted through thebore from the distal end thereof.

Further in accordance with this invention-the lower or distal end 7 ofthe barrel is adapted to threadably receive and retain a needle assemblyfor operative communication with the interior of an installed cartridge.

One form of needle assembly for this purpose is shown in FIGS. 1 and 2,with FIG. 2 specifically showing the needle assembly as it appears priorto installation and use. Here, the needle assembly is formed from asuitable plastic material and comprises a cylindrical body 20terminating at its distal end in a tapering stud 21 over which anelongated cap 22 is frictionally fitted and terminating at its proximalend in a proximally extending annular skirt 23 having an internaldiameter such as to freely receive the lower or distal end of acartridge when installed in the barrel. An inner cap or shell 24, havinga flange 25 and an annular skirt 26, fits over the body 20 with theskirt 26 surrounding the skirt 23 of the body.

The external diameter of the skirt 26 is complementary to the internalthreads of the barrel end 7 and is self-threading when fitted thereintoby rotation of the flange 25.

A double ended hypodermic needle 27 is axially embedded in the body 20with its distal end contained within the removable cap 22 and itsproximal end contained within and substantially coextensive with theskirt 23.

For shipment and storage in a sterile condition prior to use, an outercap or shell 28, having a flange 29 and an annular skirt 30, is fittedcompletely over the skirt 26 of the inner cap.

The needle assembly of FIG. 3 is identical to that of FIG. 2 except thatthe external surface of the skirt 26 is pre-threaded as at 31 for easierengagement with the threaded end 7 of the barrel.

In the modification shown in FIG. 4, the external surface of the bodyskirt is pre-threaded as at 32 and the internal cap or shell 24 iseliminated but the external cap 28 is still used for shipping andstorage purposes.

FIGS. 9 and 10 of the drawings shows a further modification of theneedle assembly in which the external surface of the body skirt of FIG.4, rather than being pre-threaded, is provided with a plurality ofsymmetrically disposed self-threading longitudinal ribs 39, each havinga chisel or feather-edged proximal end 40 for ready insertion into thethreaded end 7 of the barrel.

The syringe of this invention is particularly adapted for use withcartridges of the type (see FIGS. 1 and 5) comprising a tubular glass orother transparent body 33 having its distal end sealed by a rubber orother penetrable plug 34 and its proximal end closed by a rubber orother resilient plunger or piston 35 that may be axially reciprocatedwithin the body 33. The body 33 is dimensioned such that its distal endwill fit freely within the skirt 23 of the needle assembly and itsproximal end will fit freely within the recess 12 of the clampingelement 11.

In use for a given patient, and primarily for reasons of sterility, thesyringe should be initially prepared by bodily inserting a combinedneedle assembly and cartridge into the bottom or distal end of thebarrel (see FIG. 5) after having first removed the cap 28 from theneedle assembly and after having cleaned both ends of the cartridge witha disenfectant. At this point the clamp element 11 is threadablyadvanced through the nut 10 so that the recess 12 fits over the adjacentor proximal end of the cartridge to securely hold same in position foruse. Then the actuating or piston rod 16 is advanced so that its distalend 18 may be operably connected to the plunger or piston 35 of thecartridge.

Such a connection may be made in several ways. Thus, as shown in FIG. 7,the distal end of the rod 16 may be provided with a tapered self-tappingscrew tip 37 that may be screwed into the opposed end of the plunger 35;or, as shown in FIG. 8, the distal end of the rod 16 may be providedwith a barbed spear-point 38 that can penetrate and be retained by theopposed end portion of the plunger 35.

The needle cap 22 is then removed and the syringe is ready for use.

Should it be necessary to replace the initially installed cartridgewhile working upon a single patient, it can be done simply bydisengaging and retracting the rod 16 from its connection with theplunger 35, retracting the clamp element 11 a distance sufficient toclear the proximal end of the cartridge, and then insert a fingerthrough the window 9 to tilt the cartridge outwardly through the window8 (see FIG. 6) and remove same in a direction along its tilted axis. Afresh cartridge is then inserted in the reverse manner and the clampelement 1 1 is advanced to firmly seat the distal end of the cartridgewithin the skirt 23 of the needle assembly so that the proximal end ofthe needle 27 is forced through the seal 34 into open communication withthe interior of the cartridge.

In this manner cartridges may be installed and replaced without causingcontamination of the needle and without requiring the syringe body to beautoclaved between successive uses. In fact it is only necessary tostore the syringe body in a disenfectant solution between uses, since nopart of the needle ever contacts any part of the syringe body.

It is of course to be understood that variations in arrangements andproportions of parts may be made within the scope of the appendedclaims.

I claim:

1. A hypodermic syringe comprising a cylindrical barrel provided at itsproximal end with a removable cartridge clamping means including acartridge plunger-actuating rod, a cartridge in said barrel containing areciprocable plunger actuatable by said rod, said barrel having itsdistal end internally threaded for removably attaching a needle assemblythereto, said cartridge being sutstantially cylindrical throughout itslength, said barrel having an aperture, said aperture having a lengthand width sufficient to permit the ready insertion of said cartridge,said barrel being adapted to house said plunger-containing cartridgeintermediate its ends in peripherally spaced relation thereto throughoutits length and being constructed to permit the ready insertion andremoval of said cartridge into and out of said barrel, said cartridgebeing provided with a penetrable seal at its distal end and with saidreciprocable plunger normally positioned adjacent its proximal end, thedistal end of said plunger-actuating rod being provided with means foroperable connection with the plunger of said cartridge when saidcartridge is housed within said barrel, a needle assembly including acentral body provided with an external flange seated against the distalend of said syringe barrel, a tapered stud of reduced dimensionsprojecting from the outer end of said central body and having alongitudinal axis forming an extension of the central axis of said body,an annular wall projecting from the inner end of said central body andhaving a central longitudinal axis forming an extension of the centralaxis of said body, said annular wall being located within the distal endof said barrel and closing the distal end of said cartridge in thebarrel, said distal end of said barrel seated against the inner end ofsaid central body, said distal end of said cartridge being in non-fluidtight peripherally spaced relation with respect to said annular wall,and the periphery of said annular wall being in threaded engagement withthe internal thread at the distal end of said barrel for removablyattaching said needle assembly to said barrel, said central body,tapered stud and annular wall being of a one piece plastic construction,a double-ended hypodermic needle having an intermediate portion axiallyembedded within said body and said tapered stud, the proximal end ofsaid needle projecting axially into the space defined by said annularwall and the distal end thereof extending beyond the outer end of saidtapered stud, and the projecting proximal end of said needle penetratingthrough the penetrable sea] at the distal end of the cartridge seatedagainst said central body and enclosed by said annular wall, theprojecting proximal end of said needle being of a length less than thatof the projecting distal end thereof and less than longitudinal lengthof said annular wall.

2. A hypodermic syringe comprising in combination, a cylindrical barrelhaving a proximal end and a distal end, said barrel being formed withopposed apertures wherein one of said apertures extends substantiallythroughout the length of the barrel between the distal end and theproximal end, thread means formed on the inner circumfrential surface ofthe barrel at the distal end; a cartridge in said barrel, said cartridgebeing cylindrical and having substantially the same diameter throughoutits length said diameter being less than the inside diameter of saidbarrel and said cartridge having a penetrable seal at the distal end,said one aperture having a length and width sufficient to permit theready insertion of said cartridge, and a needle assembly having acentral body portion formed with an external flange seated against thedistal end of said syringe barrel, and an annular wall projectingupwardly toward the proximal end of the barrel from the inner end ofsaid central body portion and being coaxial with the central bodyportion, a double-ended hypodermic needle having an intermediate portionaxially fixedly disposed in said central body portion, the proximal endof said needle projecting into the space within the annular wall and thedistal end thereof extending past the central body portion, thread meanson the outer surface of said annular wall to engage said barrel threadmeans, and the inner surface of said annular wall being spaced from saidcartridge, said body and said annular wall being of a one-piece plasticconstruction, so that said cartridge is in tilted relationship with saidannular wall of the needle assembly upon insertion and removal of thecartridge through the aperture extending substantially throughout thelength of the barrel, whereby said cartridge is insertable and removablethrough the aperture extending substantially throughout the length ofthe barrel, the proximal end of said barrel or the distal end of saidbarrel.

3. The combination of claim 2, wherein the top end of the annular wallof the needle assembly extends to a point within the space of theaperture extending substantially throughout the length of the barrel.

4. The combination of claim 3, wherein the other of said aperturesextends between the distal end and the proximal end of said barrel, andis of lesser length than the first said aperture opposed thereto.

1. A hypodermic syringe comprising a cylindrical barrel provided at itsproximal end with a removable cartridge clamping means including acartridge plunger-actuating rod, a cartridge in said barrel containing areciprocable plunger actuatable by said rod, said barrel having itsdistal end internally threaded for removably attaching a needle assemblythereto, said cartridge being sutstantially cylindrical throughout itslength, said barrel having an aperture, said aperture having a lengthand width sufficient to permit the ready insertion of said cartridge,said barrel being adapted to house said plunger-containing cartridgeintermediate its ends in peripherally spaced relation thereto throughoutits length and being constructed to permit the ready insertion andremoval of said cartridge into and out of said barrel, said cartridgebeing provided with a penetrable seal at its distal end and with saidreciprocable plunger normally positioned adjacent its proximal end, thedistal end of said plunger-actuating rod being provided with means foroperable connection with the plunger of said cartridge when saidcartridge is housed within said barrel, a needle assembly including acentral body provided with an external flange seated against the distalend of said syringe barrel, a tapered stud of reduced dimensionsprojecting from the outer end of said central body and having alongitudinal axis forming an extension of the central axis of said body,an annular wall projecting from the inner end of said central body andhaving a central longitudinal axis forming an extension of the centralaxis of said body, said annular wall being located within the distal endof said barrel and closing the distal end of said cartridge in thebarrel, said distal end of said barrel seated against the inner end ofsaid central body, said distal end of said cartridge being in nonfluidtight peripherally spaced relation with respect to said annular wall,and the periphery of said annular wall being in threaded engagement withthe internal thread at the distal end of said barrel for removablyattaching said needle assembly to said barrel, said central body,tapered stud and annular wall being of a one piece plastic construction,a double-ended hypodermic needle having an intermediate portion axiallyembedded within said body and said tapered stud, the proximal end ofsaid needle projecting axially into the space defined by said annularwall and the distal end thereof extending beyond the outer end of saidtapered stud, and the projecting proximal end of said needle penetratingthrough the penetrable seal at the distal end of the cartridge seatedagainst said central body and enclosed by said annular wall, theprojecting proximal end of said needle being of a length less than thatof the projecting distal end thereof and less than longitudinal lengthof said annular wall.
 2. A hypodermic syringe comprising in combination,a cylindrical barrel having a proximal end and a distal end, said barrelbeing formed with opposed apertures wherein one of said aperturesextends substantially throughout the length of the barrel between thedistal end and the proximal end, thread means formed on the innercircumfrential surface of the barrel at the distal end; a cartridge insaid barrel, said cartridge being cylindrical and having substantiallythe same diameter throughout its length said diameter being less thanthe inside diameter of said barrel and said cartridge having apenetrable seal at the distal end, said one aperture having a length andwidth sufficient to permit the ready insertion of said cartridge, and aneedle assembly having a central body portion formed with an externalflange seated against the distal end of said syringe barrel, and anannular wall projecting upwardly toward the proximal end of the barrelfrom the inner end of said central body portion and being coaxial withthe central body portion, a double-ended hypodermic needle having anintermediate portion axially fixedly disposed in said central bodyportion, the proximal end of said needle projecting into the spacewithin the annular wall and the distal end thereof extending past thecentral body portion, thread means on the outer surface of said annularwall to engage said barrel thread means, and the inner surface of saidannular wall being spaced from said cartridge, said body and saidannular wall being of a one-piece plastic construction, so that saidcartridge is in tilted relationship with said annular wall of the needleassembly upon insertion and removal of the cartridge through theaperture extending substantially throughout the length of the barrel,whereby said cartridge is insertable and removable through the apertureextending substantially throughout the length of the barrel, theproximal end of said barrel or the distal enD of said barrel.
 3. Thecombination of claim 2, wherein the top end of the annular wall of theneedle assembly extends to a point within the space of the apertureextending substantially throughout the length of the barrel.
 4. Thecombination of claim 3, wherein the other of said apertures extendsbetween the distal end and the proximal end of said barrel, and is oflesser length than the first said aperture opposed thereto.